1. Field of the Invention
The present invention relates generally to shear resistant steel decking, and more particularly, to an apparatus for forming a shear-resistant side lap seam attachment in steel decking.
2. Description of the Relevant Art
It is common in the construction of commercial buildings to create floors and roofs from steel deck panels. Such steel deck panels might include ribbed, or “fluted”, steel deck panels as well as cellular steel deck panels. Examples of fluted steel deck panels are shown, for example, in U.S. Pat. Nos. 4,186,535 and 4,894,967. Such steel deck panels are typically welded to underlying structural support beams, although mechanical fasteners, such as power-actuated pins or screws may also be used. When properly assembled, such fluted steel deck panels provide a cost-effective diaphragm for forming floors and roofs of commercial buildings. These steel deck panels are often referred to in the trade by the names A-deck, B-deck, F-deck, N-deck, W-deck, etc. Such panels are often provided in different thicknesses, or gauges, ranging from relatively thin 22 gauge stock to more rigid 16 gauge stock. Panel widths are typically 24 inches to 36 inches, depending upon the type of steel deck being used. Individual panel lengths can vary from as little as three feet to over 40 feet. Reinforcing ribs, or “flutes”, are formed in such panels. One edge of each such panel, extending parallel to such ribs, includes an upwardly-extending lip. The opposite edge of the panel includes a downwardly-extending inverted U-shaped lip for extending over, and receiving, the upwardly-extending lip of an adjacent panel to form a seam. The two adjacent panels are attached along such seam. Various methods have been used to form the seam attachment, including button punching, crimping, screwing, riveting, welding, as well as shearing and deformation of the deck seam.
Building codes of many geographic areas require buildings to be able to withstand lateral shear forces of specified minimums. This is particularly true for regions known to be subject to high winds (e.g., the Eastern United States), earthquakes or other seismic activity (e.g., the Western United States). Steel roof decks, when properly secured to the underlying building frame, form a diaphragm. In order for the diaphragm to resist lateral shear forces without failure, the seam attachment securing the sides of adjacent panels to each other must be able to effectively resist relative sliding movement of adjacent panels along the seam joining the two panels. Often, side-lapped joints of a steel deck diaphragm must be inspected for consistency and integrity before further construction of a building may proceed. To avoid construction delays, such side-lapped joints should be formed in a manner that allows such joints to be inspected quickly and easily, preferably from the top side of the decking.
Each different seam attachment method presents benefits and disadvantages. For example, button punch tools for deforming “buttons” within the overlapped lips of adjacent panels along the side seam are relatively easy to use, and a number of such attachments can be formed in relatively little time. One such pneumatically-assisted tool for crimping and dimpling the side seam of steel decking is disclosed in U.S. Pat. No. 5,878,617 to Parker. However, such button punches do not form a very secure connection, and are not very effective at resisting lateral shear forces.
Other seam attachment tools actually shear and deform portions of the seam. For example, in U.S. Pat. No. 182,193 issued in 1876, Holeton discloses a method of forming triangular notches in the side-lapped joint and then folding over such triangular notches to interlock the joint. In U.S. Pat. No. 3,641,729, inventor Irvin discloses the use of lip-clenching dies operated by a clinching tool to cut a slit through the side-lapped joint, and to form opposing lobes for securing the side-lapped joint.
U.S. Pat. No. 6,212,932 to Parker discloses a pneumatic shear for forming structural louvers. In one embodiment, a pneumatically-operated tool selectively opens and closes a pair of jaws that are pivotally connected to each other about a common pivot axis. One such jaw includes a single blade having first and second opposing sides forming first and second blunt edges. The second jaw includes two spaced blades that are spaced from each other by the thickness of the single blade on the first jaw, also having blunt edges. Thus, the two spaced blades on the second jaw form a “die” for receiving the single blade on the first jaw when the first and second jaws are pivoted to their closed position. With the jaws in their opened position, the first and second jaws are inserted over a side-lapped seam of a steel deck. The pneumatic tool is then activated to close the jaws toward each other. The single blade of the first jaw passes between the two “die” blades of the second jaw, forming a pair of cuts in the overlapped seam. Further closing of the jaws deforms a central tab in a first direction, while deforming regions on either side of the central tab in the opposite direction. Side-lapped joints formed by use of this apparatus have been shown to securely fasten the side-lapped seams and to satisfactorily resist deformation due to horizontal shear loading.
In U.S. Pat. No. 7,434,314, issued to Morton, a further tool for reliably fastening together side-lapped edges of adjacent deck panels is disclosed. The '314 patent describes a seam attachment tool that includes four jaws, two of which are positioned on one side of the seam, and the other two of which are positioned on the opposite side of the seam. Two of the opposing jaws cooperate with each other to shear a first cut line through the seam. The other two opposing jaws cooperate with each other to shear a second cut line through seam parallel to, and slightly spaced apart from, the first cut line. The material bounded between the first and second cut lines forms a louver or tab. This material is deformed in a first direction adjacent the first cut line, and deformed in the opposite direction adjacent the second cut line. It has been found that prototypes of the seam attachment tool disclosed in the '314 Morton patent form a relatively secure seam attachment, and attain significantly higher shear resistance values than other known punching tools.
Applicant has more recently come to realize that the four-jaw punch tool disclosed in the '314 patent could be further improved. For example, the aforementioned four-jaw tool is not perfectly symmetrical. As a result, when a deck installer triggers the pneumatic actuator on a working prototype of such tool, a torque, or twisting motion, is applied to the handle of the tool, which the operator must resist. Since the deck installer typically makes many of such attachments continuously along the deck seam on a roof, the hands, wrists, and arms of the deck installer can tire easily. In addition, it was found that, when using the working prototype, the jaws of the four-jaw tool would sometimes bind in the deck seam, even after pneumatic pressure was released from the actuator of the tool. This binding of the jaws may be due to the torque exerted upon the seam by the jaws in a non-symmetrical fashion.
One of the stated objects of the invention set forth in the specification of the '314 patent is to provide a punching tool having a blade assembly that equalizes the wear on the blades, and which avoids excessive stress on any particular blade, to extend the usable life of the tool. Applicant has found that, in regard to the aforementioned working prototype, though the addition of the fourth jaw lessened the likelihood of jaw failure, it did not eliminate the problem of jaw failure. When one or more of the jaws fail, the punching tool must essentially be disassembled; the jaw with the broken blade must be detached from the actuator and replaced with a new jaw having a fresh blade. Apart from the need to keep the rather bulky replacement jaws on hand for such instances, significant time is required to disassemble the tool and repair it. During such down time, work on attaching the deck seam necessarily halts. Jaw failure can be reduced somewhat by using a harder steel to form the jaw; however, making the entire jaw from specially hardened steel significantly increases the cost of the tool; it also makes the entire jaw assembly more brittle, which allows for failures in the jaw at points other than the working blade end.
Accordingly, it is an object of the present invention to provide a punching tool for forming an attachment in an interlocking side-lapped seam of a steel deck structure which provides a solid attachment capable of resisting significant horizontal shear loads.
It is a further object of the present invention to provide such a punching tool which can be operated relatively quickly and easily by a deck installer to attach interlocking side-lapped seams of a steel deck structure.
It is a still further object of the present invention to provide such a punching tool which produces an attachment that can be quickly and easily inspected by an inspector standing atop the assembled steel decking.
Another object of the present invention is to provide such a punching tool having jaws that generally equalize the wear on the blades of such jaws, and which avoids excessive stress on any particular blade, to extend the usable life of the tool.
A yet further object of the present invention is to provide such a punching tool which can be repaired quickly and easily if a blade formed on the working end of the jaw should break.
Still another object of the present invention is to form a side-lapped seam attachment that provides higher shear values by forming an attachment which is more resistant to slippage when subjected to a horizontal load along the longitudinal axis of the side-lapped seam.
A still further object of the present invention is to provide such a punching tool which is less likely to bind in the deck seam following actuation of the tool and subsequent release of compressive forces upon the jaws of the tool, to facilitate easier disengagement of the tool from the deck when air pressure on the tool is released.
Yet another object of the present invention is to provide such a punching tool wherein the jaw assembly is symmetrical in nature, and wherein there is no twisting torque force exerted upon the tool handle as the punch tool is actuated.
These and other objects of the invention will become more apparent to those skilled in the art as the description of the present invention proceeds.
Briefly described, and in accordance with a preferred embodiment thereof, the present invention relates to a punching tool for forming an attachment in an interlocking side-lapped seam of a steel deck structure. The steel deck structure includes at least first and second steel deck panels, each such deck panel including an upturned lip along one side edge thereof, and a downwardly-directed U-shaped channel along the opposing side edge thereof. Adjacent deck panels are arranged so that the downwardly-directed U-shaped channel along a side edge of one panel is inserted over the upturned lip extending from the side edge of the adjacent deck panel.
In one preferred embodiment, the punching tool includes first and second jaws spaced apart from each other, and each having a seam-engaging blade for engaging a first wall of the seam. The tool further includes third, fourth and fifth jaws spaced apart from each other, and each having a seam-engaging blade for engaging the opposing second wall of the seam. Each of the jaws provides a cutting blade on the working end thereof for engaging the seam to be attached. An actuator, which may be pneumatically powered, selectively moves the first and second jaws either toward the third, fourth and fifth jaws to a closed position, or away from the third, fourth and fifth jaws to an opened position. As the first jaw moves from the opened position to the closed position, the seam-engaging blade of the first jaw passes at least partially between the seam-engaging blades of the third and fourth jaws. Similarly, as the second jaw moves from the opened position to the closed position, the seam-engaging blade of the second jaw passes at least partially between the seam-engaging blades of the fourth and fifth jaws.
The seam engaging blades of the third and fourth jaws are spaced apart from each other by approximately the width of the seam-engaging blade of the first jaw. In this manner, the third and fourth jaws collectively form a die for receiving the seam-engaging blade of the first jaw. Likewise, the seam engaging blades of the fourth and fifth jaws are spaced apart from each other by approximately the width of the seam-engaging blade of the second jaw. In this manner, the fourth and fifth jaws collectively form a die for receiving the seam-engaging blade of the second jaw. Finally, it should also be noted that the first and second jaws likewise form a die for receiving the seam-engaging blade of the fourth jaw. The result is that three bowed louvers are formed simultaneously side-by-side within the deck seam each time the punching tool is actuated; the center-most louver is bowed outward in a first direction, and the two surrounding louvers are bowed outward in the opposite direction. This seam attachment is highly resistant to horizontal shear forces applied along the longitudinal axis of the deck seam.
Preferably, a taper is provided on each of the above-described seam-engaging blades to aid in the release of such blades from the deck seam when the actuator of the punching tool is released. In this regard, the seam-engaging blade of the first jaw preferably includes a base region as well as a peak region that projects beyond the base region. Likewise, the seam-engaging blade of the second jaw preferably includes a base region as well as a peak region that projects beyond the base region. Ideally, the width of the peak regions of such blades is slightly less than the width of the base regions of such blades to facilitate the release of the seam engaging blades of the first and second jaws from the side-lapped seam of the steel deck structure. Stated another way, the spacing between the peak regions of the first and second jaws is slightly greater than the spacing between the base regions of the first and second jaws.
In another preferred embodiment of the invention, the punching tool includes detachable blade inserts that allow broken blades to be repaired quickly, and without disassembly of the punching tool. The detachable blade inserts are removably coupled to the working ends of the jaws, preferably by a dovetail joint. Preferably, the jaws of the tool are pivotally mounted about a jaw pivot axle, and each such dovetail joint extends along an axis that is oriented generally perpendicular to the jaw pivot axle. Providing detachable blade inserts allows for the jaws to be made of a relatively elastic type of steel or other metal having a first hardness rating on the Rockwell C scale, while allowing the detachable blade inserts to be made of a metal having a higher hardness rating on the Rockwell C scale to better shear the deck seam.
In the preferred embodiments of the present invention, the seam-engaging blades of the jaws each include a generally semi-cylindrical portion. When the actuator moves the first and second jaws toward the third, fourth and fifth jaws to the closed position, the semi-cylindrical portion of the seam-engaging blade of the first jaw passes at least partially between the semi-cylindrical portions of the seam-engaging blades of the third and fourth jaws. Likewise, the semi-cylindrical portion of the seam-engaging blade of the second jaw passes at least partially between the semi-cylindrical portions of the seam-engaging blades of the fourth and fifth jaws.
It is preferred that the semi-cylindrical portions of the first and second jaws extend about central axes that are coaxially aligned with each other. In other words, the central axis of the semi-cylindrical portion of the seam-engaging blade of the first jaw is coaxial with the central axis of the semi-cylindrical portion of the seam-engaging blade of the second jaw. Similarly, it is preferred that the semi-cylindrical portions associated with the third, fourth and fifth jaws extend about central axes that are coaxially aligned with each other. In addition, it is preferred that, when the jaws of the tool are compressed to the closed position, the central axes of the semi-cylindrical blade portions associated with the first and second jaws lie proximate to the central axes of the semi-cylindrical blade portions associated with the third, fourth and fifth jaws.
If desired, such semi-cylindrical blade portions may be provided upon detachable blade inserts of the type described above. As noted above, such detachable blade inserts may be coupled to their respective jaws by dovetail joints; each of such dovetail joints preferably extends generally perpendicular to the central axis of the generally semi-cylindrical blade portion coupled thereto. The detachable blade inserts may also be attached by mechanical fasteners, epoxy cement, solder, etc.
While the above-described embodiment of the invention using detachable blade inserts is described in conjunction with a five jaw tool, those skilled in the art will appreciate that it could also be used with a three jaw tool or a four jaw tool. In the case of a three jaw tool, the first jaw is associated with a first blade insert detachably coupled thereto for engaging a first wall of the seam. Second and third jaws are also provided, being spaced apart from each other, and generally facing the first jaw. Second and third detachable blade inserts are associated with the second and third jaws, respectively, and detachably coupled thereto for engaging the second opposing wall of the seam. As noted above, the detachable coupling is preferably achieved by using a dovetail joint.
An actuator is again provided to selectively move the first jaw relative to the second and third jaws, either moving the first jaw toward the second and third jaws into a closed position, or moving the first jaw away from the second and third jaws toward an opened position. The detachable blade insert coupled to the first jaw is initially spaced apart from the second and third jaws when the tool is in its opened position for insertion about the seam. Upon operating the actuator, the detachable blade insert coupled to the first jaw advances at least partially between the second and third blade inserts coupled to the second and third jaws. As before, the second and third detachable blade inserts form a die for receiving the first detachable blade insert. Also, as noted above, such detachable blade inserts may be tapered to be of slightly lesser widths at their peaks than at their bases to facilitate the release of the tool from the seam when the actuator of the tool is released. As also noted above, the first, second and third detachable blade inserts may be made of a “harder” steel than that used to make the first, second and third jaws. As also noted above, the detachable blade inserts may each include a generally semi-cylindrical portion extending therefrom.
Referring to
As shown best in the detailed view of
Also shown in
In
The upper ends of each jaw member are coupled by a link member to slide-action drive bolt 62. For example, the upper end of jaw member 52 is pivotally coupled by link 70 and pivot pin 71 to slide-action drive bolt 62, and the upper end of jaw member 54 is pivotally coupled by link 72 and pivot pin 73 to slide action drive bolt 62. As slide-action drive bolt 62 is forced downward within slot 64 toward pivot axle 60, links 70 and 72 cause the upper ends of jaw members 52-58 to rotate outwardly away from support brackets 24 and 26. This in turn causes the lower ends of jaw members 52-58 to pivot from their opened position to their closed position. Conversely, when slide-action drive bolt 62 is de-actuated, and pulled upwardly within slot 64 away from pivot axle 60, the lower ends of jaw members 52-58 open back up.
Once again, suitable apparatus for controlling and powering reciprocation of a slide-action drive bolt is disclosed generally in prior U.S. Pat. No. 5,878,617 to Parker. The pneumatic actuator of punch tool 50 typically operates with compressed air having a pressure ranging between 100-140 psi; this develops approximately 4,200 pounds of force on the lower ends of the jaws. Of course, the actuator used to reciprocate slide-action drive bolt 62 need not be hydraulic or pneumatic; for example, an electric motor could also be used to advance and retract slide-action drive bolt 62.
Blades 74 and 76 are adapted to simultaneously engage a first wall of the U-shaped channel at deck seam 26. Third jaw 54 includes a rounded blade 78 at its lower end; fourth jaw 56 includes a rounded blade 80 at its lower end; and fifth jaw 58 likewise includes a rounded blade 82 at its lower end. The third, fourth and fifth jaws (54, 56, and 58) are spaced apart from each other, and generally face the first and second jaws (52 and 53). Blades 78, 80 and 82 are adapted to simultaneously engage the second wall of the U-shaped channel at deck seam 26. Preferably, blades 78, 80 and 82 are formed in the same manner as blades 74 and 76.
As illustrated in
Turning briefly to the schematic of
Referring again to the schematic drawing of
In a similar manner, blades 74 and 76 of first and second jaws 52 and 53 provide a die that receives blade 80 of fourth jaw 56. Turning to
Still referring to
Now turning to
As noted earlier, one of the advantages of using detachable blade inserts is that they can be formed of material that is relatively harder than the material from which the jaw itself is formed. For example, blade inserts 116-128 are preferably made from S-7 tool steel that is heat treated to be fully hardened to within the range of 56-58 on the Rockwell “C” scale. On the other hand, jaws 52′-58′ may be formed from AISI Grade 4140, or Grade 4340, tool steel hardened to within the range of 45-48 on the Rockwell “C” scale. This allows the blades themselves to be relatively hard for shearing the deck seam, while allowing the jaws themselves to be made of a more elastic material that is not as brittle and less likely to break under repeated actuation cycles.
Of course, the other primary advantage of using such detachable blade inserts relates to ease of repair if one or more of such blade inserts should break during use. It is not necessary to disassemble jaws 52-58 from pivot axle 60′ of punching tool 50 if one or more of the detachable blade inserts should break. Rather, the broken blade insert need only be removed from its corresponding jaw, and replaced with a fresh blade insert. Likewise, if it is noticed, during routine maintenance of such tools, that one or more blade inserts are excessively worn, the worn blade inserts can easily be removed and replaced with fresh blade inserts before putting the tool back in the field, all without requiring disassembly of the tool.
As shown in
Those skilled in the art will appreciate that, while such detachable blade inserts have been described above in conjunction with a five jaw punching tool, such detachable blade inserts can provide significant advantages even when used with earlier three-jaw or four-jaw punching tools.
Still referring to
Though not required, it is preferred that the central axes about which semi-cylindrical portions 136 and 138 extend be coaxial with each other. It is also preferred, though not required, that the central axes about which semi-cylindrical portions 140, 142 and 144 extend also be coaxial with each other. In this preferred scenario, when punching tool 50 is actuated to advance the jaws to the closed position, the central axes of semi-cylindrical portions 136 and 138, and the central axes of semi-cylindrical portions 140, 142, and 144, lie generally proximate to each other.
Referring to
Turning now to
Those skilled in the art will now appreciate that a punching tool for forming an attachment in an interlocking side-lapped seam of metal decking has been described which provides a reliable attachment with improved resistance to horizontal shear forces exerted along the length of the deck seam. A punching tool provided with jaws of the type described herein can be easily operated by a deck installer to form such attachments along the deck seam relatively quickly. The resulting seam attachments can easily be inspected by someone standing atop the assembled steel decking. By providing five jaws, the wear on the various jaws is better equalized for longer life. Moreover, by using the detachable blade inserts described above, any blades which do break can be repaired quickly and easily without requiring disassembly of all of the jaws from the punching tool. In addition, the disclosed jaws are less likely to bind in the deck seam after the punching tool is actuated and then released. The orientation of the jaws is entirely symmetrical, and no twisting torque force is produced upon actuation of the tool.
While the present invention has been described with respect to preferred embodiments thereof, such description is for illustrative purposes only, and is not to be construed as limiting the scope of the invention. Various modifications and changes may be made to the described embodiments by those skilled in the art without departing from the true spirit and scope of the invention as defined by the appended claims.
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Entry |
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ICBO Evaluation Report ER-5439, Reissued May 1, 2001, “Attexor Spot Clinch Connection of Cold-Formed Structural Members”, ICBO Evaluation Service, Inc., pp. 1-3. |
ICBO Evaluation Report ER-2078P (Excerpt), Reissued Dec. 1, 2002, “Verco Steel Decks”, ICBO Evaluation Service, Inc., pp. 1-8, The Delta Grip System, ASC Steel Deck, Aug. 2002. |